Tunneling machine with concrete wall forming mechanism

ABSTRACT

THIS DISCLOSURE RELATES TO A TUNNELING MACHINE WHICH HAS A SHIELD WITH A ROTARY EXCAVATING WHEEL TO EXCAVATE A TUNNEL, A MECHANISM FOR FORMING A TUBULAR CONCRETE TUNNEL LINING OR WALL AGAINST THE TUNNEL SIDES. THE MACHINE HAS AN ELONGATED TRUSS WHICH TRAILS BEHIND THE SHEILD AND WHICH CARRIES A SPOIL REMOVING CONVEYOR AND A FLUID CONCRETE SUPPLYING CONVEYOR. THE TRUSS ALSO CONSTITUTES A TRACK FOR A CONCRETE FORM HANDLER FOR TRANSFERRING FORMS FROM THE TAIL END OF THE TRUSS TO THE HEAD END AND FOR LINING THE TUNNEL WITH SUCH FORMS.

.J. Fi. TABOR Feb. 1971 3,561,223 TUNNELING MACHINE WITH CONCRETE WALL FORMING MECHANISM 7 Sheets-Sheet l Filed July 9, 1968 \NVENTO a. Jar/NZ 79502 AT' OENEYS J.R. TABOR Feb. 9,1971;

TUNNELING MACHINE WITH CONCRETE WALL FORMING MECHANISM ,',1:.sse 7 Sheets-Sheet 2 Filed July 9 NEW ATTORNEY J- R. TABOR Feb. '9', 1971,

I TIJNNFQI J INC}v MACHINE WITH CONCRETE WALL FORMING MECHANISM Filed Ju1 9', -19s8 7 Sheets- Sheet S \NVENTOR. Jar/N E. T'HBOZ BY AIMIWIIMMLY-MW ATTO RNBY J. R. TABOR Feb. 9, 1971] v I 'TUVNNELING MACHVINEIY WITH CONCRETE WALL FORMING MECHANISM Filed July: 9,, 1968} 7 Sheets-Sheet A Y .mven 'rolz & v JOHN E. 7795a; MAMA/M Feb 9; 1971 a V J. TABOR 3,561,223

TUNNELING MACHINE WITH CONCRETE WALL FORMING MECHANISM Filed aulye, 1968 r TSIieets-Sheet s Ja/wv 2 maae A-r-roznavs TUNNELING MACHINE WITH CONCRETE WALL FORMING MECHANISM Filed July 9, 1968 J. R. TABOR Feb. 9, 1971 J 7 Sheets-Sheet 6 INVENT'CZ, Jar-ow 12 77950 J. R. TABOR Feb. 9, "1971 TUNNELING MACHINE WITH CONCRETE WALL FORMING MECHANISM Filed July 9. 1968 7 Sheets-Sheet, '7

INVENTOE JOHN 1?! 77-7502 BY W ,LTA-LQ4,M$M

ATTOENEY$ United States Patent O TUNNELING MACHINE WITH CONCRETE WALL FORMING MECHANISM John R. Tabor, 3400 Spruce St., Racine, Wis. 53403 Filed July 9, 1968, Ser. No. 743,363 Int. Cl. E01g 3/04 US. CI. 61-85 11 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Tunneling machines which both excavate and form a concrete tunnel wall are known to the art. US. Pats. 551,042 and 1,866,416 are examples thereof. Such machines are not capable of high speed tunneling and have manpower requirements which are excessive by present day standards. The machine of the present invention satisfies a need for a high speed, largely automated tunneling machine which concurrently excavates spoil and forms a smooth concrete wall about the tunnel.

SUMMARY OF THE INVENTION The tunnel making machine of the present invention is adapted not only to tunnel through the earth, but also to concurrently form a concrete wall in the tunnel. Forms for the concrete wall are erected by the machine at the head end thereof and are removed by the machine at the tail end thereof. The forms remain in place only long enough for the concrete to harden and are constantly reused, those from the tail end being transferred to the head end in a continuous process of form reuse. Removal of the forms at the tail end of the machine leaves the tunnel complete rearwardly of the machine with a smooth concrete wall or bore.

The machine has a shield with a rotary excavating wheel at the head of the shield and a truss which trails behind the shield. The truss carries a spoil removing conveyor and a fluid concrete supply conveyor. The truss also provides a track for a form handler which is movable along the truss to transfer forms from near the trailing end of the truss, where the concrete has hardened, to the front end of the truss for erection behind the excavating wheel. The machine is also provided with means to inject fluid concrete into the space between the erected forms and the tunnel sides.

The form handler and its coaction with the truss is unique. The form handler transfers large sections of forms longitudinally through the limited unobstructed space about the truss by partially folding or collapsing the form sections. The bottom form sections are rotated 180 degrees about the tunnel axis in the course of their longitudinal transfer to avoid confiict with the truss legs.

The excavating wheel of the disclosed embodiment is specifically adapted to excavate through relatively mucky earth strata which has sufiicient moisture content to be pumped out of the tunnel under pressure or which can be fluidized by the addition of water for this purpose.

The machine has additional important features, including:

(1) Shield bulkheads which can be closed off against flow of spoil to provide percent breasting at the tunnel face.

(2) A seal between the rotary wheel and shield to decrease the gap therebetween.

(3) Cutting wheel blades which are remotely controlled as to degree of opening and spoil excavating rate.

(4) A fluid concrete seal or bulkhead which can be pressed against the injected concrete to compress the concrete and eliminate voids in the concrete, fill the void behind the shield tail, fill fissures in the tunnel sides and eliminate the need for grouting operations otherwise needed to fill these voids and fissures.

(5) Fluidizing the spoil and pumping it out of the tunnel.

(6) The support for the truss by which the truss can freely advance with the shield.

Other objects, features, and advantages of the invention will appear from the disclosure hereof.

In the drawings:

FIG. 1 is an enlarged longitudinal section taken through a tunnel and the head end of a tunneling machine embodying the present invention.

FIG. 2 is a simplified longitudinal section on a reduced scale through a tunnel and showing substantially the complete length of a tunneling machine embodying the invention.

FIG. 3 is a front elevation of the machine, showing in particular the face of the cutting wheel.

FIG. 4 is a fragmentary cross section taken along the the line 4-4 of FIG. 3.

FIG. 5 is a fragmentary cross section taken along the line 5-5 of FIG. 3.

FIG. 6 is a vertical cross section taken along the line 6-6 of FIG. 1.

FIG. 7 is a fragmentary enlarged detail view of the power mechanism for actuating the gates in the cutting wheel.

FIG. 8 is a fragmentary cross section taken along the broken line 8-8 of FIG. 7.

FIG. 9 is a fragmentary cross section taken along the line 9-9 of FIG. 1.

FIG. 10 is a cross section taken along the curved line 10-10 of FIG. 9.

FIG. 11 is an enlarged cross section taken along the line 11-11 of FIG. 9.

FIG. 12 is a fragmentary cross section through the tunnel, showing the mode of supporting the truss on the concrete forms.

FIG. 13 is a section taken along the line 13-13 of FIG. 12.

FIG. 14 is a vertical longitudinal section taken through the tunnel and showing in elevation the form handler mounted on the truss.

FIG. 15 is a cross section taken along the line 15-15 of FIG. 14.

FIG. 16 is a cross section taken along the line 16-16 of FIG. 14.

FIG. 17 is a cross section taken through the tunnel and showing the form handler in the course of handling a partially collapsed top form section.

FIG. 18 is a similar cross section showing the form handler in the course of handling a partially collapsed bottom form section.

FIG. 19 is a side elevation of the form handler, a portion of this view being shown in vertical longitudinal section.

FIG. 20 is a diagrammatic view of a set of mating top section and bottom section concrete liner forms, the forms being shown in spaced apart relation.

3 FIG. 21 is a fragmentary view, partly in section, showing the shield advanced to open a space to receive a form section at the head end of the liner.

FIG. 22 is a perspective view of the form handler.

PREFERRED EMBODIMENT OF THE INVENTION Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure.

THE SHIELD AND CUTTING WHEEL Tunnel shaft 30 is formed by a tunneling machine within a shield 31. The shield has an annular bulkhead 32 near its head end on which an excavator such as rotary cutting wheel 33 is supported on a bearing 34. The wheel 33 has an annular diaphragm 35 with a central opening 36 into which projects the hopper 37 of a spoil removing tubular conveyor 38.

Bearing 34 is similar to the one shown in my copending US. patent application Ser. No. 474,351, filed July 23, 1965, now Pat. No. 3,382,002 in that the bearing may be removed axially as a unit from the bulkhead 32 and from the wheel 33. Repair and replacement of the bearing 34 can thus be effectuated without having to remove the wheel itself.

Bearing 34 consists of a series of bearing balls 41 captive between an outer race 42 and an inner race 44. Outer race 42 is releasably mounted on the wheel diaphragm 35 by a series of bolts 43. Inner race 44 is releasably mounted on mounting ring 46 by a series of bolts 45. Mounting ring 46 is releasably mounted on annular bulkhead 32 by a series of bolts 47.

Upon release of the several bolts in the series of bolts 43 and 47, the bearing structure 34, which includes the inner race 44, outer race 42, balls 41 and ring 46, can be withdrawn axially rearwardly into the shield for repair or replacement of the bearing, without requiring withdrawal of the wheel.

Wheel 33 is driven by a series of reversible hydraulic motors 48 which are clustered about the opening 36 in the bulkhead 32. Motors 48 have drive sprockets 51 respectively engaged with a drive ring 52 mounted on the wheel diaphragm 35. Ring 52 is provided with roller pegs 53 engaged by the sprockets 51 and by which thrust from the motors 48 is smoothly transmitted to the wheel 33 without substantial friction. Motors 48 are selectively powered to drive the wheel 33 clockwise or counter clockwise.

Most of the front of wheel 33 is closed by a face plate having a central flat portion 54 and an outer frustoconical margin 59. The face plate is provided with radially elongated openings 55 in which radially elongated gates 56 are pivotally mounted on the pintles 57 which span laterally across the openings 55. The gates 56 are V-shaped in front elevation and have outer portions 58 radially outwardly of the pintles 57 and inner portions 61 which are radically inwardly of the pintles 57. The inner portions 61 have their proximate inner ends connected on swing links 62 to a rotatable coupling 63 (FIG. 7) further connected by shaft 64 to a right angle motion transmitting coupling 65 powered by fluid motor 66. By this mechanism the gates 56 are concurrently swung about their pintles 57 to adjust the degree of opening between the gates and the wheel face 54, 59. When the gates 56 are closed, substantially no spoil can flow through the wheel. The tunnel face will then be substantially entirely breasted by the wheel.

From FIGS. 4 and 5, it is clear that when the gates 56 are open, the radially outward portions 58 thereof project forwardly of the wheel face portion 59. Gate portions 61 are retracted rearwardly of the face portion 54. In open position, gate portions 58 function as cutting blades to cut spoil from the tunnel face and bring it in through the opening 55. The wheel face plate 54 also acts as a cutting blade to bring spoil through the opening 55 near 4 the center of the wheel. For cutting purposes, gate portions 58 are provided with cutting edges 67, and the face plate portion 54 is provided with cutting edges 68.

The center of the wheel is provided with a nose plate 71 having cutting blades 72 mounted thereon, thus to cut spoil from the tunnel face opposite the center of the wheel.

The shaft 64 which opens and closes the gates 56 is mounted on the rotating axis of wheel 33. The rotary coupling 63 permits the shaft 64 to be non-rotatable while the wheel rotates. The right angle drive is mounted on a shelf 73 (FIG. 1), in turn mounted on a second or inner bulkhead disk of plate 74 is removably disposed in the central opening in annular bulkhead 32. The edge of plate 74 is retained on bulkhead 32 in a grooved circular bearing 75 in which the plate 74 can rotate under the power of fluid motors 70 (FIG. 6). The motors 70 are controlled to maintain plate 74 in a position to support the tube 38 and truss level and in proper centered relation in the tunnel, regardless of any tendency of the shield to roll under counter torque of the Wheel 33. It has circular opening 76 through which the spoil conveyor tube 38 extends. Disk 74 is sealed to the tube 38 about the opening 76 by flexible sealing strip 79. When gates 56 are closed, there art two bulkheads in tandem to breast the tunnel. The closed face wheel 33 acts as one bulkhead and the bulkhead 32 with its closed center disk 74 acts as a second bulkhead.

To increase the effectiveness of the breasting action of wheel 33, the shield is provided with an inwardly projecting flange or seal 69 (FIG. 1) adjacent the wheel 33. Flange 69 overlaps the edge of wheel 33 to impede flow of mucky spoil into the wheel around its periphery. Accordingly, spoil is kept out of bearing 34 and from between the wheel drum 33 and shield wall. This prevents encrustation and spoil compaction which would interfere with wheel rotation and require increased wheel torque to rotate the wheel.

The right angle coupling 65 (FIG. 7) comprises spaced cam slides 77 which are mounted to slide on ways 78. Respective slides 77 have corresponding inclined cam slots 81 which receive the cross pin 82 on shaft 64. Fluid motor 66 has a piston rod 83 pivotally connected on the pin 84 to the slides 77 and by which the slides are actuated to thrust shaft 64 in either direction axially of the tunnel for the purpose of adjusting the position of the gates 56. Shaft 64 moves axially in bearing 70 welded to bulkhead disk 74.

THE SPOIL CONVEYOR The wheel 33 is provided with spoil lifting flights 85 which subdivide the periphery of the wheel into a series of buckets into which spoil admitted into the wheel 33 is deposited and carried upwardly toward the top of the wheel from 'whence the spoil is dropped into the hopper 37. Hopper 37 is at the front end of the tube 38 which contains an auger 86. Auger 86 is turned under power by hydraulic motor 132. Teeth 87 are formed in the portion of the auger flight which is in hopper 37 in order to break up clods of spoil.

The disclosed embodiment is intended primarily to tunnel through a mucky earth stratum in which the spoil will be relatively flowable. Flowability can be enhanced by injecting water into the tube 38 from a water manifold pipe 88 which has a series of outlets 89 spaced along tube 38. Water manifold 88 receives water from the hose 91 which is supported by the elongated truss 92 which trails behind shield 31. The fluidized spoil or muck is pumped by muck pump out of tube 38 through down spout 40 and thence out of the tunnel through hose 134 which is carried by truss 92 and leads out of the tunnel to a place of disposal.

THE TRUSS The forward end of the truss 92 is supported by the conveyor tube 38 which rests on a series of radial thrust rollers 93 mounted on shelf 73. Shelf 73 also has a series of axial thrust rollers 94 which bear axially on a thrust flange 95 fast to the tube 38 near its front end. The portion of the conveyor tube 38 embraced by portions of the truss 92 are securely fastened to the truss so that the truss is both supported at its front end by the tube 38 and is drawn forward with the tube as the shield moves forwardly in the tunnel shaft.

As best shown in FIG. 2, the truss 92 is supported at its rear end on a wheeled carriage 96 which rides on the floor of the concrete tunnel wall 97. At several locations along its length, the truss 92 is provided with shiftable roller supports 98 which rest upon the bottom section concrete forms 103 which line the bottom of the tunnel ahead of carriage 96.

THE CONCRETE LINER FORMS Forms 103 are foldable or collapsible and have a novel coaction with the truss and a form handler so that the concrete wall 97 is formed continuously as the shield 31 moves forwardly in the course of excavating the tunnel.

There are also top section forms 102 which together with bottom section forms 103 completely line the tunnel shaft. A set of mating forms 102, 103 is shown in spaced apart, diagrammatic relation in FIG. 20. Each form comprises a pair of curved reinforced plates 104, pivoted together on a hinge 105. The plates are provided on their inner faces with a grid pattern of braces, as is conventional. When the respective top and bottom form sections 102, 103 are expanded to circular cross section and are bolted together end-to-end, they form a continuous tem-' porary liner within the tunnel shaft and define an annular space 109 between the outer surface of the connected forms 102, 103 and the tunnel shaft wall 30 within which fluid concrete is injected to form the concrete tunnel wall 97.

THE CONCRETE INJECTING APPARATUS FIGS. 1, 9, and 11 illustrate how the concrete is injected. The truss 92 carries a fluid concrete supply conveyor or hose 1.12. This hose terminates in a manifold 113 (FIG. 9) having several flexible hoses 114 which are lead to ports 115 in a flexible annular concrete injection sealing nozzle or bulkhead 116, details of which are best shown in FIGS. 9, 10 and 11. Nozzle -116 is made to span across the space 109 to confine the pressure of the fluid concrete injected into space 109 through the hoses 114. Nozzle 116 includes a rubber or other elastomeric gasket or seal 117 which is reinforced at one side by a series of curved inner plates 120 about each port .115, and on the outside by a series of progressively longer overlapping spring plates 121, and a back-up plate 122. These parts are held together in assembled relation by bolts 123.

The inherent resiliency of the gasket 117 and the fact that it is not continuously reinforced throughout its circumference gives the bulkhead 116 a certain flexibility, as is indicated in FIG. 10. Accordingly, the bulkhead can yield locally to accommodate for different back pressure conditions. Each back-up plate .122 is subject to the pressure of a hydraulic jack 124, the base end of which reacts against the fixed annular bulkhead 32 of the shield 31. Each jack 124 has a piston 125 'pivotally connected at 126 (FIG. 1) to the back-up plate 122. The pressure existing within the jacks 124 will determine the back pressure exerted on the fluid concrete which has just been injected into the space behind the bulkhead 116.

There is another set of hydraulic jacks .127 utilized to advance the shield forwardly in the tunnel. Jacks 127 are also seated against the bulkhead 32 at one end and have extending pistons 128 with suitable shoes 129 seated against the annular end of the last set of forms 102, 103. Controlled pressure exerted on the jacks 127 will thrust the shield 31 forwardly in the tunnel. Controlled pressure on a pump in fluid concrete conveyor line 112 Will inject concrete through the nozzle or bulkhead 116 and controlled pressure on the jacks 124 will establish the necessary back pressure on the concrete. The operator of the machine has control over all the fluid motors and the concrete pump so as to balance the various pressures to insure injection of fluid concrete at substantially the same rate as the shield moves forwardly under pressure of the jacks 127. The operator also controls the motors 48 which turn the wheel 33, the motor 132 which turns the screw 86, etc.

Maintenance of control pressure on the injected concrete will insure a solid and compacted fill of the space between the forms 102, 103 and the shaft wall 30, notwithstanding any voids or fissures adjacent said wall into which the concrete tends to leak. These voids simply fill with concrete and become part of the wall. Moreover, the void which otherwise would be formed behind the tail end 133 of shield 31 will also be filled under such pressure.

FIGS. 1 and 21 illustrate various possible positions of the parts illustrated therein, depending upon the sequence used by the operator to successively or concurrently perform various control functions. These figures are merely illustrative, as there are many other positions of the parts, depending upon the sequence selected by the operator.

FIG. 1 illustrates a sequence in which fluid concrete is injected over a newly emplaced set of head end forms 102, 103 while the cutting wheel 33 is inactive. After the concrete has filled the space 109 to the extent indicated in FIG. 1, injection of concrete is discontinued and the jacks 127 are pressurized to advance the shield and the cutting wheel 33 is rotated to excavate spoil. During this movement, pressure is maintained on jacks 124 in order to maintain pressure on the concrete, notwithstanding the forward movement of the shield.

When the parts reach the position suggested in FIG. 21 at approximately the maximum extension of jacks 124, 127, the pistons 128 of jacks 127 are contracted to leave space for the insertion of another set of head end forms 102, 103.

Thereafter, the concrete injecting sequence can either *be concurrent or alternate with respect to the shield advancing and spoil excavating functions.

In order to provide ample time for the concrete between the forms 102, 103 and the tunnel shaft 30 to harden, the forms are left in position along a considerable length of the tunnel, as is illustrated in FIG. 2. The truss 92 is slightly longer than the over-all length of the emplaced forms. In a practical embodiment of the invention, truss 92 is 240 feet long.

THE TRUSS SUPPORT CRADLES The head end of the truss is supported on the shield, and the tail end of the truss is supported on dolly 96. Intermediate portions of the truss are supported on the shiftable support cradles or legs 98. The shiftable cradles 98 have curved base pads 144 which rest by gravity on the forms 103 behind which the concrete is setting. Each pad 144 has sufficient length to span across adjacent end flanges on the bottom forms 103. Pads 144 carry upwardly projecting legs 142 with upwardly exposed end wheels 141 which provide a rolling support for the truss 92. At spaced locations along its length, the undersurface of truss 92 is provided with sets of laterally spaced facing channel tracks 140. Each track set extends longitudinally of the truss for a relatively short distance, for example, 20 feet. Wheels 141 of the cradles 98 are embraced by the flanges of the tracks and rollably support the truss.

Each cradle 98 has four wheels 141 and four legs 142 which have their lower ends interconnected to the pad 144 on pintles 143. The respective front legs and rear legs are cross connected by respective front and rear brackets 139 which carry threaded sleeves 147 for the screw jack 146 which connects the front and rear sets of legs.

When the truss 92 has been drawn forwardly by the advancing movement of the shield 31 a suflicient distance so that the wheels 141 are near the rear ends of the tracks 140, cradles 98 are shifted ahead to a new advanced position on the floor provided by forms 103. Only one cradle 98 is shifted at a time. While one cradle is being shifted, the truss is supported by the other cradles, the shield 31 and the dolly 96. Shifting of any one cradle 98 is accomplished by its screw jack 146 which spans between the legs 142. The end of the screw jack 146 is connected to an electric motor 148. When the motor is energized to turn the screw 146 in one direction, the legs 142 will be spread, thus to lift the pad 144 to its position shown in FIGS. 12 and 13 in which it is elevated slightly above the floor of forms 103. Wheels 141 will now suspend the cradle 98 from flanges of the channel tracks 140. The cradle 98 is now free to be shifted forward manually. Wheels 141 will roll ahead on the tracks 140 until the cradle is repositioned at a forward location. Motor 148 is then reversed to lower the pad 144 onto forms 103 where it will again span adjacent flanges 145 thereof. Wheels 141 will again contact the upper flanges of the channel tracks 140 to rollably support the truss 92. Each cradle 98 is shifted in turn until all have been repositioned.

THE FORM HANDLER Form sections 102, 103 near the tail end of the truss 92, where the concrete has hardened and set, are periodically transferred by a form handler 151 to the leading end of the truss 92. Form sections thus transferred are erected and repositioned ahead of the concrete injecting apparatus 116, etc. in spaced relation to the shield wall and-in endwise connection to previously erected forms. Accordingly, the form sections 102, 103 are repeatedly reused and are continuously being shuttled from the rear end of the truss to the head end of the truss.

Form handler 151 is ensleeved over the truss 92 and is sihftable longitudinally therealong. Form handler 151 has a generally cylindrical shape (FIG. 22), except that it is open at its bottom, to clear the truss support cradles 98 as it moves along the truss 92 (FIG. 16). The truss 92 is provided with outwardly facing channel-shaped tracks 153 (FIG. 15). The form handler 151 comprises a trolley 163 with a hollow interior with flat vertical side walls to fit adjacent the sides of the truss 92. In cross section the form handler has a horseshoe shape. Near its top, trolley 163 carries wheels 154 which ride in the truss tracks 153. Near its bottom the form handler trolley has guide rollers or wheels 155 which bear laterally on longitudinally extending tracks 156 near the lower edge of the side walls of the truss 92 .(FIGS. 14, 15).

The form handler 151 is propelled longitudinally along the truss 92 in any convenient manner. In the disclosed embodiment, cable 157 is strung along the side of truss 92. Cable 157 is engaged by drive pulleys 158 (FIGS. 14 and 19) mounted on a power box 161 which includes a hydraulic motor 162 to turn the pulleys 158 and pull the handler 151 forwardly or backwardly along the fixed cable 157. Motor 162 is reversible to propel the form handler selectively in both directions along the truss.

As best shown in FIGS. 16 and 17, the trolley 163 of form handler 151 includes a curved arch 164 which carries roller bearings 165 on which outer form carrier sleeve or shell 166 is rotatable. Shell 166 is generally cylindrical except where it is open along one side. Trolley 163 also carries additional wheels 167 for support and guidance of the rotatable shell 166. Shell 166 is rotated about the rollers 165, 167 by motor 168 (FIGS. 14 and 19) which has a drive sprocket 169 engageable with rack 172 formed on the inside of the shell 166. Rack 172 desirably comprises a series of roller pegs extending from a drive ring 152. Accordingly, the shell 166 can be rotated about the axis of the truss 92 between its positions respectively shown in FIGS. 17 and 18.

The purpose of rotating the shell 166 as aforestated is to shift form sections 103 from the bottom of the tunnel to the top of the tunnel and to transfer the form sections through an unobstructed space about the top and sides of the truss and thus avoid interference with the truss cradle legs 98.

Carrier shell 166 carries two fluid cylinders 173 which are respectively anchored at one end on pins 174 near the edges of the shell. When the form handler is not carrying a form, the other ends of the cylinders 173 are secured in slings 175 (FIG. 14).

When it is desired to transfer one of the form sections, for example, top form section 102, from the tail end of the tunnel to the head end of the tunnel, the form handler 151 is driven to a position opposite the tail end form section 102 and cylinders 173 are extended and pinned to suitable brackets 176 with which the form sections are provided. Coupling 177 is also extended and attached to bracket 178 on the form sections adjacent the hinge when the curved leaf sections 104 are hinged. The end bolts 181 which attach the tail end form section to the lining are then removed. The cylinders 173, 177 are then retracted to their positions shown in FIG. 17 in which the form section 102 is withdrawn from the concrete wall 97 and the leaf sections 104 thereof are partly collapsed or folded toward each other.

Note that the end rails 182 of top form sections 102 are slanted at 182 to facilitate sliding them off of the oppositely slanted end rails 183 of the bottom form secions 103. This permits the leaves 104 of the upper form section to collapse radially inwardly. The form handler 151 may now be advanced to the head end of the truss 92, carrying the form section 102 through the unobstructed top and side space about the truss 92. Cradles 98 of the truss extend downwardly between the ends of the horseshoe opening in the form carrier 151 so that the legs do not interfere with this longitudinal movement of the form carrier and its load.

The transfer of the bottom form section 103 involves an additional manipulation inasmuch as this form is at the bottom of the tunnel and cannot be simply shifted longitudinally because the cradles 98 of the truss obstruct the space beneath the truss and would interfere with this movement. Accordingly, the form handler 151 is retracted to a position near the tail end of truss 92 and is aligned with the tailmost bottom form section 103 from which top form section 102 has previously been removed. Shell 166 is rotated 180 about trolley 163 to its bottom-most position shown in FIG. 18, and its cylinders 173, 177 are coupled to the said form section 103. Cylinder 173, 177 are manipulated to collapse form section 103 inwardly, as shown in FIG. 18. Then the form carrier shell 166 is rotated through 180 again to bring it to its position shown in FIG. 17, where the form 103 will be shifted in line with the unobstructed top and side space about the truss 92.

As shown in FIG. 2, there is one more bottom form section 103 than top form section 102. This is because the bottom form must be emplaced at the head end of the tunnel before the top form is emplaced, in order to interlock the slanted ends 182, 183 at the form ends. In making the longitudinal shift of forms, the extra bottom form section 103 is first shifted forwardly into its bottom position at the head of the liner and then a top form section 102 is moved to the head of the tunnel, and erected on the top of the previously emplaced bottom form section 103.

The sequence of erecting the partially collapsed form sections at the head end of truss 92 is as follows.

Partially collapsed bottom form section 103 arrives at the end of the truss 92 after the shield 31 has been pushed forward a distance somewhat greater than the length of one form section. The pistons 128 of shield pushing jacks 127 are then retracted, as shown in FIG. 21, so that suflicient space is provided ahead of the liner within which another set of form sections 102, 103 can be received. The form carrier 151 with its lower formsection 103 will be aligned with the space 150. Cylinders 173, 177 will be manipulated to expand the leaves 104 of the form section 103 and erect it into place. The end rails of the form sections are then bolted to the corresponding end rails of the next adjacent form at the head end of the liner.

After the bottom form section 103 is thus erected, the form handler 151 returns to the tail end of the truss and picks up the taihnost top form section 102 and transfers it to the head end of truss as aforestated. Form handler 151 is aligned with the space 150 above the previously positioned lower form section 103, and its cylinders 173, 177 are manipulated to unfold and erect the form section 102 into place where it is bolted to the next adjacent top form section.

In this manner a form set comprising complementary top and bottom form sections 102, 103 is shifted from the rear of the truss 92 to the head of the truss 92. Pistons 128 of cylinders 127 are now placed against the most recently erected form sections. The shield advancing and concrete injecting procedure are now resumed.

What is claimed is: 1. A tunneling machine with concrete wall forming mechanism comprising:

a shield, an excavator carried at the head of the shield, a truss trailing said shield, a spoil removing conveyor carried by the truss, a fluid concrete conveyor carried by the truss, a plurality of concrete forms for lining the tunnel in spaced relation to the wall formed by the excavator,

injecting means carried by the shield to inject concrete supplied by said concrete conveyor into the space between the forms and the tunnel wall to form a concrete wall about the tunnel,

and a form handler movable along the truss to transfer forms from near the trailing end of the truss where the concrete has hardened to the front end of the truss for erection behind said excavator.

2. The machine of claim 1 in which the spoil removing conveyor comprises means to convey mucky spoil, said excavator comprising a wheel having a face which can be substantially closed to breast said spoil.

3. The machine of claim 2 in which the shield has a substantially fixed bulkhead spaced longitudinally from said wheel and which also is substantially completely closed, whereby two spoil barriers in tandem resist flow of fluid spoil.

4. The machine of claim 1 in which said spoil removing conveyor comprises a screw auger, means for fluidiz-,

ing the spoil as it is acted on by the auger and a pump to pump fluidized spoil.

5. The machine of claim 1 in which the truss has legs by which it is supported in elevated position from the tunnel floor, the space about said truss being substantially unobstructed except in the vicinity of said legs, said form handler comprising means to convey forms through said unobstructed space to avoid said legs.

6. The machine of claim 5 in which said unobstructed space is at the top and sides of the truss, said forms comprising top form sections and bottom form sections, said form handler further comprising means to transfer a bottom form section to a position at the top and sides of the truss in substantial alignment with said unobstructed space and convey it through said space to the head end of the tunnel.

7. The machine of claim 6 in which said form handler comprises an open bottom trolley having a hollow interior within which the truss is received, said truss having tracks on which the trolley is movable longitudinally along the truss, said trolley having a form carrier rotatable thereabout to shift forms from the bottom of the truss to the top of the truss.

8. The machine of claim 1 in which said truss has legs by which it is supported on said forms, and means for shifting said legs longitudinally along the truss to advance said legs with respect to the tunnel.

9. The machine of claim 1 in which said excavator comprises a wheel having a substantially closed front face with radially elongated openings, transversely extending pintles spanning said openings at a point intermediate the radial extent thereof and gates swingable on said pintles to selectively open and close said openings, gate portions at one side of the pintle moving outwardly beyond the front wall as gate portions at the other side of the pintle move inwardly of said wall.

10. The machine of claim 1 in which said injecting means comprises an annular concrete bulkhead to seal the space between the wall of the shield and the concrete forms spaced therewithin, said concrete bulkhead having ports through which concrete is pumped into said space.

11. The machine of claim 10 in further combination with means to impose back pressure on said concrete bulkhead to maintain pressure on the concrete in said space.

References Cited UNITED STATES PATENTS 748,809 1/1904 Stone 6l-85 1,351,137 8/1920 Sheen 6l--84 3,206,824 9/1965 Cerutti 6l42X 3,247,675 4/1966 Winberg 6l-85X 3,355,215 11/1967 Haspert et a1 299-3 1X 3,379,024 -4/ 1968 Wohlmeyer 29933X 3,382,002 5/1968 Tabor 2993 1X FOREIGN PATENTS 715,426 8/1965 Canada 6l85 DENNIS L. TAYLOR, Primary Examiner US. Cl. X.R. 

